Respiratory distress syndrome associated with prematurity, sepsis and birth asphyxia is a major reason for the mortality of newborns worldwide with over three million newborns dying annually and a much larger number disabled, particularly in resource limited regions, worldwide. Oxygen therapy delivered via a continuous positive airway pressure (CPAP) device is the most common treatment to address respiratory compromise in these infants. However, pure oxygen can place the infant at significant risk of oxygen-related damage to the lungs, eyes and brain. A conventional CPAP device is therefore connected to both a compressed air and oxygen tank to control the oxygen content delivered. The conventional CPAP is often prohibitively expensive in low income regions worldwide, requiring uninterrupted electricity, a compressed air tank which isn?t easily available and is insufficiently portable for healthcare workers to treat newborns in remote areas worldwide. A bubble-CPAP (bCPAP) is a simpler, much less expensive device, and has been implemented in resource limited areas of several African and Asian countries. However, improvised bCPAP devices deliver 100% oxygen, thus placing infants at significant risk of organ damage. In this proposal, we hypothesize that a bubble CPAP device equipped with an adjustable Venturi ambient air-oxygen blender will deliver oxygen enriched air efficiently at a controlled percentage ranging from 30 to 80%. As our pilot data on fixed Venturi blenders of different designs shows, the fraction of oxygen delivered depends on their geometry. The Specific Aims are: first, to test the hypothesis that a modular, adjustable Venturi air-oxygen blender can deliver a controlled fraction of oxygen, ranging from 30-80%, in a bCPAP device by designing and fabricating the blender, and measuring the fraction of oxygen delivered; second, to test the hypothesis that the bCPAP device will deliver oxygen efficiently by measuring the minimum flow rate of oxygen required to operate the bCPAP at each fraction of oxygen delivered. Successful completion of this project will allow us to develop a bCPAP device that enables the health care provider the flexibility to dial up the oxygen content as needed without having to change blenders, which would disrupt the treatment and subject the infant to asphyxia in the interim period, thus endangering the infant. Furthermore, this ultra-low cost device requires no electricity and no air tank since it draws in ambient air into the oxygen stream, making it substantially more portable than a conventional CPAP device. Our team has already conducted field-testing and implemented a bubble CPAP package using a fixed Venturi air-oxygen blender in healthcare facilities in Kenya and India, where it is conducting training of local healthcare workers to improve screening, diagnosis and treatment of respiratory conditions of newborns. Our goal is to decrease respiratory newborn mortality by 50% within two years of implementation of our ultra-low cost, bubble CPAP device whose critical component will be our innovative, adjustable ambient air-oxygen blender that we hope to design, fabricate, test and optimize in this proposal.